Abner g



(No Modelj I A. G. TISD EL.

Telephone Transmitter.

'Nb. 237,341; Patented Feb. 1, i881.

I WITNESSES: geg/ N-PEI'ERS. PHOTO LITHGRAFHER. WASHINGTON, D C.

UNITED T STATES PATENT FFICE. I

ABNEB c. TIsDEL, or BROOKLYN, ASSIGNOR TO ERNEST MARX, OF NEW YORK, N. Y. r

TELEPHONE-TRANSM ITTER.

SPECIFICATION forming part of Letters Patent No. 237,341, dated February 1, i881.

' Application filed September 24, 1880. (No model.)

furthermore, the musical sound-vibrations that tend to obscure the transmission of articulated sounds are neutralized or done away with; and the invention consists of a transmittingtelephone, the carbon button of which is mounted upon a strained metallic ribbon or band, which is rigidly attached to one end of .a-solid bridge, while'the opposite end is at- 1: tached to an adjustable straining-block.

The invention consists, secondly, of a damper-block attached to the straining-ribbon by means of a spring-band; and, lastly, of supporting the diaphragm on raised rests of the main frame of the transmitter. In the accompanying drawings, Figure 1 represents a rear elevation of my improved transmitting-telephone; Fig.2, a vertical horizontal section of the same on line as m, Fig. 1; and Fig. 3 is a detail rear view of the annular main frame of the transmitter, showing the supporting-rests of the diaphragm;

Similar letters of reference indicate corresponding parts.

In the drawings, A represents the annular main frame of the transmitter, and B the vibrating diaphragm of the same, which is lined around its circumference with rubber, as usual in telephones. The diaphragm rests on three or more seats, a, at the inside of the frame A, by which the diaphragm is made more sensitive to the sound-vibrations, as the contactsurface with the rim of the frame A is made very small, instead of extending all around the entire circumference. The (liaphragm is, furthermore, not liable to stick to the frame or be impeded by dustor otherwise. The dia phragm B and seats or rests'a are encircled by a raised annular shoulder, a, of greater height than the seats, which shoulder, like the seats,

is cast in one piece with frame A. The diaphragm is retained by means of spring-contacts O, as shown in Fig. 1. The'annular main frame A is cast at diametrically-opposite points with supports b, to one of which is firmly attached, by aconnecting spring-plate, d, a solid bridge-piece, D. To the opposite post, b,is applied a bracketplate, d, with setscrew 61 which set-screw bears upon the free end of the bridge-piece D, and serves to adjust the same nearer to or farther away from the vibrating diaphragm B.

The carbon button E is mounted centrally upon a metallic band or ribbon, E, which is rigidly secured at one end to the bridge-piece D, and at the opposite end to a strainingblock, E, that is capable oflateral adjustment toward or away. from the opposite end of the bridge-piece by a set-screw, 0. This adjustable straining-block serves to impart a greater or less degree of tension to the metallic ribbon, so as to render it more or less sensitive to the vibrations of the diaphragm B. This forms an essential point of my construction, as thereby a firm and reliable support is imparted to the carbon button, and the same is thereby not liable to be thrown back too far from the platinum contact-point of the diaphragm by the vibrations of the same, but is kept permanently at a uniform distance therefrom.

To the carbon button E is attached a spring- I band, F, intermediately between the strained metallic ribbon and the bridge, which springband carries at its outer end a Weighted dam per-block, F. A contact-pin, f, of the damper-block is faced with soft rubber, and forms contact with the ribbon E, it serving to neutralize any excess of vibrations of the same, and also themusical sounds, which, to a greater or less extent, tend to obscure the articulated sounds transmitted by the telephone. This damper-block forms an important auxiliary to the button-carryingribbon, and renders the trausmitting-telephone more reliable and effective in practical use.

Having thus described myinvention, I claim as my invention and desire to secure by Letters Patent- 1. In a transmitting-telephone, the combination of the vibrating diaphragm B with a ringshaped main frame, A, having raised seats a. and a raised annular shoulder, a, encircling the diaphragm B, substantially as set 5 forth.

2. In a ,transmitting-telephone, the combi-' nation with the adjustable bridge-piece D, of a metallic straining ribbon or band, E carrying the carbon button, said ribbon being per- 10 manently attached at one end of the bridge,

and at the other end to an adjustable strainin g-block, substantially as and for the purpose set forth. a

3. In a-transmitting-telephone, the combinaattached to a spring-band. and provided with a rubber-faced contact-pin substantially as specified.

In testimony that I claim the foregoing as 20 my invention I have signed my name, in presence of two witnesses, this 16th day of September, 1880.

' ABNER G. TISDEL.

Witnesses:

PAUL GOEPEL, CARL KARP. 

